Eurail passes cover most train travel in Austria, Belgium, Croatia, Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Romania, Serbia, Slovenia, Spain, Sweden, and Switzerland. The passes do not cover travel in Boznia-Herzegovina, Bulgaria, Great Britain, Macedonia, Montenegro, Poland, Slovakia and Turkey.
If you're over 25 years old, you must buy a first-class pass. If you're 25 or under, you may buy first- or second-class passes. You can buy passes good for consecutive days, or flexipasses which only count the days you actually travel. Also available are Rail & Drive Passes, which combine train travel with car rental.
Once you have planned your trip and chosen the right Eurail pass, go to Eurail.com to purchase your pass. Choose your type of pass. Choose your currency: U.S. dollar, euro, or Australian dollar. Buy your pass and have it shipped to you.